|
Spinal Cord
Injury
Spinal cord injuries
cause
myelopathy
or damage to
nerve
roots
or myelinated fiber tracts that carry signals to and from the brain. Depending on its
classification and severity, this type of traumatic injury could also damage the gray matter in the
central part of the cord, causing segmental losses of interneurons and motorneurons. Spinal cord
injury can occur from many causes, trauma, car accident, slip and fall, diving accident,
truck accident, and motorcycle accident.
Classification of Spinal
Cord Injury
The American Spinal Injury
Association (ASIA) defined an international classification based on neurological responses, touch
and pinprick sensations tested in each dermatome , and strength of ten key muscles on
each side of the body, i.e. shoulder shrug (C4 ), elbow flexion (C5 ), wrist extension (C6 ), elbow extension (C7 ), hip flexion (L2 ).
Traumatic spinal cord injury is
classified into five categories by the American Spinal Injury Association and the International
Spinal Cord Injury Classification System:
-
A indicates a "complete" spinal cord injury where no motor or sensory function is
preserved in the sacral segments S4-S5.
-
B indicates an "incomplete" spinal cord injury where sensory but not motor function
is preserved below the neurological level and includes the sacral segments S4-S5.
This is typically a transient phase and if the person recovers any motor function
below the neurological level, that person essentially becomes a motor incomplete,
i.e. ASIA C or D.
-
C indicates an "incomplete" spinal cord injury where motor function is preserved
below the neurological level and more than half of key muscles below the
neurological level have a muscle grade of less than 3, which indicates active
movement with full range of motion against gravity.
-
D indicates an "incomplete" spinal cord injury where motor function is preserved
below the neurological level and at least half of the key muscles below the
neurological level have a muscle grade of 3 or more.
-
E indicates "normal" where motor and sensory scores are normal. Note that it is
possible to have spinal cord injury and neurological deficits with completely
normal motor and sensory scores.
Spinal Cord Injury
Syndromes
In addition, there are several
clinical syndromes associated with incomplete spinal cord injuries.
-
-
Brown-Séquard syndrome results from injury to
one side with the spinal cord, causing weakness and loss of proprioception on the
side of the injury and loss of pain and thermal sensation of the other
side.
-
Anterior cord syndrome results from injury to
the anterior part of the spinal cord, causing weakness and loss of pain and thermal
sensations below the injury site but preservation of proprioception that is usually
carried in the posterior part of the spinal cord.
-
Tabes Dorsalis results from injury to
the posterior part of the spinal cord, usually from infection diseases such as
syphilis, causing loss of touch and proprioceptive
sensation.
-
Conus medullaris syndrome results from
injury to the tip of the spinal cord, located at L1
vertebra.
-
Cauda equina syndrome is, strictly
speaking, not really spinal cord injury but injury to the spinal roots below the L1
vertebra.
Spinal Cord Injury
Statistics
In the U.S., there are
currently 1.3 million individuals living with spinal cord injuries- a number five times that
previously estimated in 2007. 61% of spinal cord injuries occur in males, and 39% in females. The
average age for spinal cord injuries is 48 years old. There are many causes leading to spinal cord
injuries. These include motor vehicle accidents (24%), work-related accidents (28%),
sporting/recreation accidents (16%), and falls (9%).
Severity of Spinal Cord
Injury
|
